Treatment of textile fabrics for imparting antishrink properties thereto



Patented Aug. 26, 1952 V TREATMENTOF TEXTItE FABRICSFOR HWPARTING ANTISHHugh vom Hove; Newport, England; assighor of; one-half to Walkden Makin& (lo/Limited,

Openshaw Manchester, England t No Drawing. Application August 23, 1949;Serial NK PRQPERTIES No.'11 1,971. In Great Britain August 28, 1948 Thisinvention relates to improvements in processes for imparting anti-shrinkproperties to textile fabrics composed of or containing regen- "eratedcellulose fibres and-is particularly applicable for the treatmentof'crepe fabrics. f "Pr'ocesses for such purpose are known in which thefabricis impregnatedwith the pre-condensates of urea-formaldehyderesinsand which; formaldehyde alone is employed to alter thehydr'ophilic properties, thetreatment being carried .out in 'thepresence of a strong acid catalyst.

A further proposal has been to use acetone ferinaldehyde condensationproducts and 1 it has i also been suggested to use glyoxal alone orwithotherbompounds such as the pm-condensates of'urea-formaldehyde or ofmelamine formaldehyde in thepresence of polyvinyl alcohol.

: Furthermore, it has been suggested; when employing the" pre-condensates of urea formaldehyde in order to prevent theformationofsubstances of high molecular structure, to carry out the process in twobaths, the first batheontain- "ing urea, preferably withcertainmetalssalts, at a concentration of about 20% and the second -bath-being-astrong formaldehyde-solution of from20%to 40%. I Thejprimary object ofthe present invention is to provide a novel process for imparting anti-"mma roperues to'textile fabrics containing regenerated cellulose whichis carriedout in two separate stages} whereby improvedfanti shrinkproperties are-irnparted tcf such fabrics, the swelling capacity of suchfabrics is reduced, and the fastnss of such fabrics to light isincreased.

The process according to the present invention uses two separatebaths,the first bath containingeither: v. i i

(a) A weak organic acid'which isnearly in soluble in water and havingone or more alcohol-hydroxylgroups and ammonia, or v (bl A similar weakorganic acid, together with ammonia, an organic amine base such as urea,

1 :fiClaims. (01.117 7) After complete impregnation in the first baththe fabric is dried (with or without dimensional control) at atemperature of between 60 (Land 120 C, Aftertreatment in the second baththe fabricis dried within the same range of temperature underdimensional control such as on awstentengiving an over stretch of 2% to3% -in-the weft and overfed in the warp; "Ihefabric is then baked at atemperature of about 150 C for about'6 to 8 minutes and the process is'completedby a short'soaping treatment with the additidns of a smallamountof ammonia to remove any free formaldehyde remaining in thefabric. The'followingexamples in which the quantities are by weight aregiven as illustrative of the inveritionv Exa'm'plei w A green dyedcrepeof 36 inch width containing100% regenerated cellulose (viscose) in bothwarp and weft is impregnated at normal tein perature in a bath inwhich-the ratio of clothto liquidis 'about lz4'containing from 1.5%tb'2i3% of pure-ricinoleic acid, 0.35% to 0.6% concen- :trated ammoniaand about 0.5 of a {suitable known softener, the pH value of thebathb'eing about 8. l a "After complete impregnation of theiabric it issqueezedin a pad mangle at a' pressurepf about 200 to 250 lbs. persquare inch so that it contains about 80% of the liquid; and dried'ofi'adr'um dryer at a'temperature of from 60 C.

v The dried fabric is then impregnated again at normal temperaturein asecond bath'contain ing between 2.5% and 5% antimony lactate and 5% to7% of formaldehyde, squeezedin a pad mangle until it contains about 80%of the'liquid,

dried on a stenter with about 2% stretch {in-the thiourea;melamine,-hydroxylamine, benz'idine or para-phenylendiamines and thesecond bath containing formaldehyde" of medium concentration andantimony lactateor antimony tartrate, when the first bath contains no,organic amine base the amount of the organic acid shouldbe berinsed anddried V weft at'a temperature of from C.to C and, when dry, baked forabout 6 to 8 minutes ata temperature of about C. c- After bakingthefabric is washed in a bath containing about 0.5% of a neutral soapand about0.5% concentrated ammbrliaiit isthen well The following tablegives a comparisonof ui fabric before and after treatment in the dry Sati a T n Shrinkfstge percent ens e 8 er 7 Stretch strength ingrammespement lstwash 2nd 3rd Untreated fabric e 194 24.7 19.5 20 Treatedfabric199 24.4 1.4 1.4 1.4

Moreover theswelling capacity is reduced from 78% in"? the; untreatedfabric to 36% in the treated fabric:

Example 2 A black morrocain cloth of 36" width having a warp of 100%cellulose acetate and a-weft of 50% cellulose acetate and 50% viscose isimpregnated at normal temperature in a bath in which the ratio of clothto liquidis-about 1:4 contain:

ing 7.5% to 10. urea, 0.3% to 0.6% ,ricinoleic acid or beta oxynaphthicacid and about 0.2% concentrated ammonia. l

After impregnation the fabric is dried, treated lna second bath andbaked as described in Example 1.

The following table gives a comparison of the fabric in the dry statebefore and after treatj swelling capacity is reduced from 83% in theuntreated fabric to 33% in the treated-fabric.

It. is found in many cases that the treatment of or containingregenerated cellulose not only imparts anti-shrink properties to thefabric but also increases fastness of the fabric to light.

Iclaim: r

. 1.' A process for, imparting anti-shrink proper;

ties to textile fabrics containing at leasta sub- ,stantial amount ofregenerated cellulose, consisting .-in treating such a fabric. at normaltem- .peraturein'a bath containing a weak organic bath containing a weakorganic selected from the-group consisting of ioleicg ricinoleic,

caproic and lauric acid, ammonia, and an organic amine base selectedfrom the group consisting of urea, thiourea, melamine, hydroxylamine,benzidine and para-phenylendiamine, until completely. impregnatedtherewith, drying the impregnated fabric at a temperature between 60 ,C.and 120 (3., impregnating the dried fabric at normal temperature in asecond bath containing formaldehyde having a substantially toconcentration, and the antimony salt of a weak organic acid selectedfrom the group conaccording to the invention of afabric composed acidselected from the group consisting of oleic, 1

ricinoleic, caproic and lauric acid, ammonia and an organic amine baseselected from the group consisting of urea, thiourea, melamine,hydroxylamine, benzidine and para-phenylendiamine, runtil completelyimpregnated therewith, drying the thus impregnated fabric, treating thedried impregnated fabric: in a second bath; containing formaldehydehaving a substantially 20% to 10%; concentration, and the antimony saltof an organic, acid selected from the group consisting oflactic-acidandtartaric acid, drying the impregnated. fabric, and baking the driedimpregnated fabric.

2. A process as defined in claim 1, wherein the organic [acid employedin the first bathis-ricinoleic acid.

3. A process as definedin claim 1, wherein the organic amine baseemployed in the first bath is urea. v

' lofsubsta 'ntially from 605C. to

1 4. process asdefined in claim 1,;wherein the organic amine baseemployed in the first bathis melamine. ,7

1,5. A processlfo'r imparting anti-shrink properties'to textile fabricscomposed mainly at least of regenerated cellulose, which comprisesimpregnating such a fabric at normal temperature in a sisting oflacticacid and tartaric acid until the fabric is completely impregnatedtherewith, drying the impregnated fabric while under an over stretch of2% to 3% inthe Weft and an overfeed in the warp, bakingthedriedimpregnated fabric at a temperature ofabout C. for about fi t08. minutes, and finally giving the baked fabric a soaping treatment-Jwith the addition of an amount of ammonia sufficient to remove any freeformaldehyde remaining in the fabric. I

A -process for imparting anti-shrink propr ertiesto textile fabricscomposed mainly at least of regenerated cellulose, which comprisesimpregnating such a fabric at normal temperature in a bath-ofliquidcontaining from 0.3% to 0.6%

0.2%ic'oncentratedammonia, and which bath the ratio-of fabric to liquidis; substantially 1:4,

until impregnation of the fabric, with ;the-;1iquid bath is complete,vdry-ing the thus-.impregnated r fabric at a temperature ofsubstantiallyqfiw, C. to 12 Off (2., subsequently impregnating such T dried impregnated fabric at normal temperature; ina secondbath of liquidcontaining substantially between 2.5% and 5% ;of the antimonysalt pf anorganic acidselected from the group consisting of formaldehyde having aconcentration of -substantially between 20% and 40%, until impregnationof the fabric with the liquid-.in-the second ba i'si'com lete ryi the.imi sna ea rabuc from. the second bath whileunder substantially 2% to' 3%stretch in the weft at a temperature 7 I r r r g 20? 0;, and bakingthedried impregnated-fabric for-from S te 8 minutes t a empe at re sb ta tial y; 3C.

5. A PROCESS FOR IMPARTING ANTI-SHRINK PROPERTIES TO TEXTILE FABRICSCOMPOSED MAINLY AT LEAST OF REGENERATED CELLULOSE, WHICH COMPRISESIMPREGNATING SUCH A FABRIC AT NORMAL TEMPERATURE IN A BATH CONTAINING AWEAK ORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF OLEIC,RICHINOLEIC, CAPROIC AND LAURIC ACID, AMMONIA, AND AN ORGANIC AMINE BASESELECTED FROM THE GROUP CONSISTING OF UREA, THIOUREA, MELAMINE,HYDROXYLAMINE, BENZIDINE AND PARA-PHENYLENDIAMINE, UNTIL COMPLETELYIMPREGNATED THEREWITH, DRYING THE IMPREGNATED FABRIC AT A TEMPERATUREBETWEEN 60* C. AND 120* C., IMPREGNATING THE DRIED FABRIC AT NORMALTEMPERATURE IN A SECOND BATH CONTAINING FORMALDEHYDE HAVING ASUBSTANTIALLY 20% TO 40% CONCENTRATION, AND THE ANTIMONY SALT OF A WEAKORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF LACTIC ACID ANDTARTARIC ACID UNTIL THE FABRIC IS COMPLETELY IMPREGNATED THEREWITH,DRYING THE IMPREGNATED FABRIC WHILE UNDER AN OVER STRETCH OF 2% TO 3% INTHE WEFT AND AN OVERFEED IN THE WARP, BAKING THE DRIED IMPREGNATEDFABRIC AT A TEMPERATURE OF ABOUT 150* C. FOR ABOUT 6 TO 8 MINUTES, ANDFINALLY GIVING THE BAKED FABRIC A SOAPING TREATMENT WITH THE ADDITION OFAN AMOUNT OF AMMONIA SUFFICIENT TO REMOVE ANY FREE FORMALDEHYDEREMAINING IN THE FABRIC.